Turbo fan and air conditioner having the same

ABSTRACT

A turbo fan including backward-inclined blades that are inclined in a direction opposite to a rotating direction of a rotating plate. A positive pressure surface of each blade, facing the rotating direction of the rotating plate, takes the form of a flat surface, and a negative pressure surface of the blade, opposite to the rotating direction of the rotating plate, takes the form of a convexly-curved surface. A radius of curvature defined by the convexly-curved negative pressure surface is within a range of 2.5˜4 times of a radius of the turbo fan. The turbo fan can reduce noise and consumption of power together, and consequently, an air conditioner having the turbo fan can achieve an improvement in performance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 2006-0126374, filed on Dec. 12, 2006 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present general inventive concept relates to a turbo fan and an air conditioner having the same, and, more particularly, to a turbo fan which can reduce noise and consumption of power, and an air conditioner having the turbo fan.

2. Description of the Related Art

Generally, blowing fans serve to blow air by a rotational force, and are used in a refrigerator, air conditioner, vacuum cleaner, etc. The blowing fans may be classified into an axial flow fan, a sirocco fan, a turbo fan, etc., according to their air suction and discharge manners and their shapes.

Of the various fans, the turbo fan is configured such that air is sucked in an axial direction of the fan, and then, discharged in a radial direction from between blades of the fan. The turbo fan has no need for an additional duct because it allows air to be naturally introduced into the fan and discharged to the outside. By virtue of such a structural advantage, the turbo fan is widely used in various fields.

Considering the configuration of a general turbo fan, the turbo fan includes a rotating plate defining a rear surface of the fan, to which a fan motor is mounted, a plurality of blades radially arranged on the rotating plate with a predetermined interval, and a shroud defining a front surface of the fan.

The shroud is centrally formed with a suction opening, through which air is suctioned. A discharge opening for discharging the suctioned air is defined between the rotating plate and the shroud in a circumferential direction.

If the rotating plate is rotated by operation of the fan motor, the blades, which are integrally formed with the rotating plate, are rotated simultaneously, thereby allowing air to be suctioned in an axial direction through the suction opening and the suctioned air to be discharged in a radial direction through the discharge opening.

Meanwhile, the blades have an air-foil shape, and are arranged radially about a shaft of the fan motor between the rotating plate and the shroud.

The blades installed between the rotating plate and the shroud may have various installation angles. On the basis of their installation angle, the blades may be classified into a forward-inclined type and a backward-inclined type.

When using backward-inclined blades that are inclined in a direction opposite to a rotating direction of the rotating plate, the turbo fan has high operational efficiency (in view of consumption of power), but suffers from relatively loud noise because the revolution per minute of the fan has to be increased. On the other hand, when using forward-inclined blades that are inclined in the same direction as the rotating direction of the rotating plate, the operational efficiency of the turbo fan is poor (in view of consumption of power) although the turbo fan causes less noise.

SUMMARY OF THE INVENTION

The present general inventive concept provides a turbo fan which can reduce noise while achieving improved operational efficiency, and an air conditioner having the turbo fan.

Additional aspects and/or advantages of the general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.

The foregoing and/or other aspects and utilities of the present general inventive concept may be achieved by providing a turbo fan including: a rotating plate connected with a drive unit, blades radially arranged on the rotating plate, and a ring-shaped shroud mounted to face one surface of the rotating plate, wherein a positive pressure surface of each blade, facing a rotating direction of the rotating plate, takes a form of a flat surface, and a negative pressure surface of the blade, opposite to the rotating direction of the rotating plate, takes a form of a convexly-curved surface.

A radius of curvature defined by the convexly-curved negative pressure surface may be within a range of 2.5˜4 times of a radius of the turbo fan.

The blades may take a form of backward-inclined blades, which are inclined in a direction opposite to the rotating direction of the rotating plate.

The foregoing and/or other aspects and utilities of the present general inventive concept may be achieved by providing an air conditioner including: a body having an air suction opening and an air discharge opening; a heat exchanger provided in the body and adapted to perform heat exchange of air suctioned through the suction opening; and a turbo fan including a rotating plate connected with a drive unit, blades radially arranged on the rotating plate, and a ring-shaped shroud mounted to face one surface of the rotating plate, the turbo fan serving to suction the air from the suction opening and blow the suctioned air toward the heat exchanger, wherein a positive pressure surface of each blade, facing a rotating direction of the rotating plate, takes a form of a flat surface, and a negative pressure surface of the blade, opposite to the rotating direction of the rotating plate, takes a form of a convexly-curved surface.

A radius of curvature defined by the convexly-curved negative pressure surface may be within a range of 2.5˜4 times of a radius of the turbo fan.

The blades may take the form of backward-inclined blades, which are inclined in a direction opposite to the rotating direction of the rotating plate.

The foregoing and/or other aspects and utilities of the present general inventive concept may be also achieved by providing a turbo fan, including a rotating plate to connect to a drive member, a plurality of blades connected at one side to the rotating plate and inclined in a direction opposite to a rotating direction of the rotating plate, each of the blades being shaped to have at least one curved surface, and a ring shaped shroud connected to opposite sides of each of the plurality of blades from the side connected to the rotating plate.

A positive pressure surface of each blade can take a form of a flat surface and a negative pressure surface of each blade can take a form of a curved surface.

The foregoing and/or other aspects and utilities of the present general inventive concept may be also achieved by providing an air conditioner including: a body having an air suction opening and an air discharge opening; a heat exchanger provided in the body and adapted to perform heat exchange of air suctioned through the suction opening; and a turbo fan to suction the air from the suction opening and blow the suctioned air toward the heat exchanger, the turbo fan including: a rotating plate to connect to a drive member, a plurality of blades connected at one side to the rotating plate and inclined in a direction opposite to a rotating direction of the rotating plate, each of the blades being shaped to have at least one curved surface, and a ring shaped shroud connected to opposite sides of each of the plurality of blades from the side connected to the rotating plate.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and utilities of the exemplary embodiments of the general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, of which:

FIG. 1 is a perspective view showing a turbo fan consistent with an exemplary embodiment of the present general inventive concept;

FIG. 2 is a front view of the turbo fan illustrated in FIG. 1;

FIGS. 3A and 3B are front views illustrating comparative examples of the turbo fan consistent with the exemplary embodiment of FIG. 1;

FIGS. 4A and 4B are graphs, respectively, illustrating the relationship of noise and air flow and the relationship of air flow and consumed power, depending on the turbo fan illustrated in FIG. 2 and the comparative turbo fans illustrated in FIGS. 3A and 3B;

FIG. 5 is an enlarged view illustrating a blade of the turbo fan illustrated in FIG. 2;

FIGS. 6A and 6B are graphs, respectively, illustrating the relationship of noise and air flow and the relationship of air flow and consumed power, depending on a variation in the radius of curvature of a negative pressure surface of the blade illustrated in FIG. 5; and

FIG. 7 is a sectional view illustrating an air conditioner having the turbo fan consistent with an exemplary embodiment of the present general inventive concept.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to a turbo fan and an air conditioner having the same consistent with exemplary embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below to explain the present general inventive concept by referring to the figures.

As illustrated in FIG. 1, the turbo fan 1, according to an exemplary embodiment of the present general inventive concept, includes a rotating plate 10 adapted to be rotated by a drive unit (not illustrated) that is connected to the center of the rotating plate 10, a plurality of blades 20 radially arranged on the rotating plate 10, the blades 20 being integrally formed with the rotating plate 10, and a ring-shaped shroud 30 coupled to distal ends of the blades 20 so as to face one surface of the rotating plate 10.

The rotating plate 10 has a hub 11 that is configured to receive the drive unit, for example, a fan motor, connected to the center of the rotating plate 10 for rotation of the rotating plate 10. The hub 11 also serves to guide flow of air, which is introduced through an inner periphery 31 of the shroud 30 and discharged from between the blades 20. The rotating plate 10 also has a boss portion 12 formed at the center of the hub 11, the boss portion 12 internally defining a shaft bore to couple, for example, a shaft of the fan motor, and vent holes 13 perforated in the hub 11 to cool the fan motor. The vent holes 13 guide cool air to the fan motor, to cool the fan motor.

The ring-shaped shroud 30, which is coupled to the distal ends of the blades 20 integrally formed with the rotating plate 10, has the inner periphery 31 and an outer periphery 32, to allow air to be axially introduced into the turbo fan 1 and discharged radially from the turbo fan 1.

The shroud 30 is centrally perforated with a suction opening 30 a, through which air is suctioned. A discharge opening 30 b to discharge the suctioned air is defined between the rotating plate 10 and the shroud 30 in a circumferential direction.

Generally, the blades 20 are integrally injection molded with the rotating plate 10, and the shroud 30 is generally coupled to the distal ends of the blades 20 by thermal fusion or ultrasonic fusion. Alternatively, the shroud 30 also may be integrally injection molded together with the rotating plate 10 and the blades 20.

The inner periphery 31 of the shroud 30, as illustrated in FIG. 1, protrudes outward by a predetermined length, such that air to be suctioned into the fan 1 can be efficiently guided toward the blades 20 through the inner periphery 31 of the shroud 30.

FIG. 2 is a front view of the turbo fan 1 illustrated in FIG. 1.

As illustrated in FIG. 2, the turbo fan 1 according to the present exemplary embodiment of FIG. 1 includes the plurality of blades 20 arranged between an outer periphery of the hub 11 and the outer periphery 32 of the shroud 30. The blades 20 are radially formed about the boss portion 12 formed at the hub 11.

Strictly speaking, the blades 20 do not extend radially from the boss portion 12. The blades 20 are inclined in a direction opposite to a rotating direction of the rotating plate 10. Accordingly, the blades 20 are backward-inclined blades.

To improve the operational efficiency of the turbo fan 1, each blade 20 is shaped to have at least one curved surface. In the turbo fan 1 of FIGS. 1 and 2, one surface of the blade 20 facing the rotating direction of the rotating plate 10, namely, a positive pressure surface 20 a takes the form of a flat surface, and the other surface of the blade 20 opposite to the rotating direction of the rotating plate 10, namely, a negative pressure surface 20 b takes the form of a curved surface.

FIGS. 3A and 3B are front views illustrating turbo fans consistent with two comparative examples for comparing with the turbo fan 1 having the flat positive pressure surface 20 a of the blade 20, in view of noise and consumed power.

FIG. 3A illustrates the comparative turbo fan (hereinafter, referred to as “A type”) in which the positive pressure surface 20 a of the blade 20 takes the form of a convexly-curved surface, and FIG. 3B illustrates the comparative turbo fan (hereinafter, referred to as “B type”) in which the positive pressure surface 20 a of the blade 20 takes the form of a concavely-curved surface.

In the present general inventive concept, an experiment is conducted to compare the performance of the turbo fan 1 in which the blade 20 has the flat positive pressure surface 20 a, with performances of the comparative A-type and B-type turbo fans.

On the basis of results of the above experiment performed on the three types of different turbo fans, FIG. 4A illustrates the relationship of noise and air flow, and FIG. 4B illustrates the relationship of air flow and consumed power.

As can be appreciated from FIG. 4A, under the condition of the same air flow among the three types of turbo fans illustrated, the turbo fan 1 consistent with the embodiment of FIGS. 1 and 2 has less noise than the A-type and B-type turbo fans.

Also, as can be appreciated from FIG. 4B, under the condition of the same air flow among the three types of turbo fans illustrated, the consumed power of the turbo fan 1 consistent with the embodiment of FIGS. 1 and 2 is slightly greater than that of the A-type turbo fan, but is remarkably less than that of the B-type turbo fan.

Comparing the above three types of turbo fans with reference to FIGS. 4A and 4B, the A-type turbo fan has a problem of having a greater amount of noise than the turbo fan 1 of FIGS. 1 and 2, although it has slightly superior performance, in view of consumed power, than the turbo fan 1. Also, the B-type turbo fan has inferior performance, in view of both noise and consumed power, than the turbo fan 1 consistent with the embodiment of FIGS. 1 and 2.

Judging from the above experimental results, accordingly, it will be appreciated that the turbo fan 1 of FIGS. 1 and 2 having the flat positive pressure surface 20 a of the blade 20 is the most advantageous in view of performance.

Meanwhile, under the assumption that the positive pressure surface 20 a of the blade 20 is a flat surface, the experiment for testing the performance of the turbo fan depending on the shape of the negative pressure surface 20 b was performed. In this case, the positive pressure surface 20 a was a flat surface, whereas the negative pressure surface 20 b was a flat surface or convexly-curved surface.

FIG. 5 is an enlarged view illustrating the blade 20 of the turbo fan 1 illustrated in FIG. 2.

As illustrated in FIG. 5, the radius of the turbo fan 1 is designated as “d,” and the radius of curvature of the negative pressure surface 20 b is designated as “r.” In this case, a ratio of the radius of curvature r of the negative pressure surface 20 b to the radius d of the turbo fan 1 is designated as “R,” and the formula of R=r/d is obtained.

On the basis of the value of R as experimentally calculated, FIG. 6A illustrates the relationship of noise and air flow, and FIG. 6B illustrates the relationship of air flow and consumed power.

As can be appreciated from FIG. 6A, under the condition of the same air flow among the three types of turbo fans as illustrated, the greatest amount of noise is generated when the value of R is zero (hereinafter, “R=0” means that the negative pressure surface of the blade takes the form of a flat surface), and the least noise is generated when the value of R is 4 or 6.

Also, as can be appreciated from FIG. 6B, under the condition of the same air flow, consumed power is maximized when the value of R is 6, and is minimized when the value of R is 0, 2, or 4.

Judging from the results illustrated in FIGS. 6A and 6B, it can be concluded that the value of R is preferably within a range of 2.5˜4 in order to reduce both noise and consumption of power together. Accordingly, the turbo fan 1 consistent with the embodiment of FIGS. 1 and 2 is designed such that the ratio R of the radius d of the turbo fan 1 to the radius of curvature r of the negative pressure surface 20 b is within the range of 2.5˜4.

As described above, when the blade 20 has the flat positive pressure surface 20 a and the radius of curvature r of the negative pressure surface 20 b of the blade 20 is within a range of 2.5˜4 times of the radius d of the turbo fan 1, the turbo fan 1 consistent with the embodiment of FIGS. 1 and 2 can achieve a reduction in both noise and consumption of power together.

FIG. 7 is a sectional view illustrating an air conditioner having the turbo fan 1 according to another exemplary embodiment of the present general inventive concept.

As illustrated in FIG. 7, the ceiling-mounted air conditioner includes a box-shaped body 50 having an opened lower surface, the body 50 being mounted in a ceiling 41 through an opening 42 of the ceiling 41, and a lower panel 60 mounted to a lower end of the body 50 and configured to cover both the lower surface of the body 50 and the opening 42 of the ceiling 41.

A blowing device 52 is mounted in the center of the body 50 and adapted to endow indoor air with a blowing force. Also, a heat exchanger 53 is mounted around the blowing device 52 and adapted to cool or heat air discharged from the blowing device 52. The lower panel 60 has a center suction opening 61, and a discharge opening 62 around the suction opening 61.

The blowing device 52 includes the turbo fan 1 similar to that of the embodiment of FIGS. 1 and 2, which is designed to suction air axially from the center thereof and discharge the suctioned air radially, and a fan motor 2 secured to an inner top surface of the body 50. The heat exchanger 53 is mounted around the turbo fan 1 such that the air blown by operation of the turbo fan 1 is heat exchanged while passing through the heat exchanger 53. A supporting member 54 is mounted in a lower region of the body 50 and used to support the heat exchanger 53. The supporting member 54 also serves to collect and discharge condensate water falling from the heat exchanger 53.

In the ceiling-mounted air conditioner having the above described configuration, if the blowing device 52 within the body 50 is operated, the air, which is suctioned into the body 50 through the suction opening 61, is heat exchanged while passing through the heat exchanger 53. As the heat exchanged air is supplied back into a room, the cooling or heating of the room can be accomplished.

By installing the turbo fan 1 of FIGS. 1 and 2 to the ceiling-mounted air conditioner of FIG. 7, the air conditioner can achieve a reduction in noise and consumption of power. Although the above description deals with the ceiling-mounted air conditioner having the turbo fan 1 of FIGS. 1 and 2, it will be appreciated that the turbo fan 1 can be installed in a variety of other air conditioners and other various electronic appliances.

As apparent from the above description, the turbo fan consistent with the embodiments of the present general inventive concept has the effects of reducing both noise and consumption of power together and achieving an improvement in performance.

When mounting the turbo fan to an air conditioner, furthermore, it is possible to reduce noise and consumption of power of the air conditioner.

Although a few embodiments of the present general inventive concept have been illustrated and described, it should be appreciated by those skilled in the art that changes may be made herein without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the claims and their equivalents. 

1. A turbo fan comprising: a rotating plate connected with a drive unit; blades radially arranged on the rotating plate; and a ring-shaped shroud mounted to face one surface of the rotating plate, wherein a positive pressure surface of each blade facing a rotating direction of the rotating plate takes the form of a flat surface, and a negative pressure surface of the blade facing opposite to the rotating direction of the rotating plate takes the form of a convexly-curved surface.
 2. The turbo fan according to claim 1, wherein a radius of curvature defined by the convexly-curved negative pressure surface is within a range of 2.5˜4 times a radius of the turbo fan.
 3. The turbo fan according to claim 1, wherein the blades take the form of backward-inclined blades, which are inclined in a direction opposite to the rotating direction of the rotating plate.
 4. An air conditioner comprising: a body having an air suction opening and an air discharge opening; a heat exchanger provided in the body and adapted to perform heat exchange of air suctioned through the suction opening; and a turbo fan including a rotating plate connected with a drive unit, blades radially arranged on the rotating plate, and a ring-shaped shroud mounted to face one surface of the rotating plate, the turbo fan serving to suction the air from the suction opening and blow the suctioned air toward the heat exchanger, wherein a positive pressure surface of each blade, facing a rotating direction of the rotating plate, takes the form of a flat surface, and a negative pressure surface of the blade, opposite to the rotating direction of the rotating plate, takes the form of a convexly-curved surface.
 5. The air conditioner according to claim 4, wherein a radius of curvature defined by the convexly-curved negative pressure surface is within a range of 2.5˜4 times of a radius of the turbo fan.
 6. The air conditioner according to claim 4, wherein the blades take the form of backward-inclined blades, which are inclined in a direction opposite to the rotating direction of the rotating plate.
 7. A turbo fan, comprising: a rotating plate to connect to a drive member; a plurality of blades connected at one side to the rotating plate and inclined in a direction opposite to a rotating direction of the rotating plate, each of the blades being shaped to have one curved surface; and a ring shaped shroud connected to opposite sides of each of the plurality of blades from the side connected to the rotating plate.
 8. A turbo fan according to claim 7, wherein a positive pressure surface of each blade takes a form of a flat surface and a negative pressure surface of each blade takes a form of a curved surface.
 9. An air conditioner comprising: a body having an air suction opening and an air discharge opening; a heat exchanger provided in the body and adapted to perform heat exchange of air suctioned through the suction opening; and a turbo fan to suction the air from the suction opening and blow the suctioned air toward the heat exchanger, the turbo fan including: a rotating plate to connect to a drive member, a plurality of blades connected at one side to the rotating plate and inclined in a direction opposite to a rotating direction of the rotating plate, each of the blades being shaped to have one curved surface, and a ring shaped shroud connected to opposite sides of each of the plurality of blades from the side connected to the rotating plate. 